i8254: Factor out base class for KVM reuse

Applying the concept used for the *PICs once again: establish a base
class for the i8254 that can be used both by the current user space
emulation and the upcoming KVM in-kernel version. We share most of the
public interface of the i8254, specifically to the pcspk, vmstate, reset
and certain init parts.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 307 insertions, 0 deletions

diff --git a/hw/i8254_common.c b/hw/i8254_common.c
new file mode 100644
index 0000000..6373e87
--- /dev/null
+++ b/hw/i8254_common.c
@@ -0,0 +1,307 @@
+/*
+ * QEMU 8253/8254 - common bits of emulated and KVM kernel model
+ *
+ * Copyright (c) 2003-2004 Fabrice Bellard
+ * Copyright (c) 2012      Jan Kiszka, Siemens AG
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#include "hw.h"
+#include "pc.h"
+#include "isa.h"
+#include "qemu-timer.h"
+#include "i8254.h"
+#include "i8254_internal.h"
+
+/* val must be 0 or 1 */
+void pit_set_gate(ISADevice *dev, int channel, int val)
+{
+    PITCommonState *pit = PIT_COMMON(dev);
+    PITChannelState *s = &pit->channels[channel];
+    PITCommonClass *c = PIT_COMMON_GET_CLASS(pit);
+
+    c->set_channel_gate(pit, s, val);
+}
+
+/* get pit output bit */
+int pit_get_out(PITChannelState *s, int64_t current_time)
+{
+    uint64_t d;
+    int out;
+
+    d = muldiv64(current_time - s->count_load_time, PIT_FREQ,
+                 get_ticks_per_sec());
+    switch (s->mode) {
+    default:
+    case 0:
+        out = (d >= s->count);
+        break;
+    case 1:
+        out = (d < s->count);
+        break;
+    case 2:
+        if ((d % s->count) == 0 && d != 0) {
+            out = 1;
+        } else {
+            out = 0;
+        }
+        break;
+    case 3:
+        out = (d % s->count) < ((s->count + 1) >> 1);
+        break;
+    case 4:
+    case 5:
+        out = (d == s->count);
+        break;
+    }
+    return out;
+}
+
+/* return -1 if no transition will occur.  */
+int64_t pit_get_next_transition_time(PITChannelState *s, int64_t current_time)
+{
+    uint64_t d, next_time, base;
+    int period2;
+
+    d = muldiv64(current_time - s->count_load_time, PIT_FREQ,
+                 get_ticks_per_sec());
+    switch (s->mode) {
+    default:
+    case 0:
+    case 1:
+        if (d < s->count) {
+            next_time = s->count;
+        } else {
+            return -1;
+        }
+        break;
+    case 2:
+        base = (d / s->count) * s->count;
+        if ((d - base) == 0 && d != 0) {
+            next_time = base + s->count;
+        } else {
+            next_time = base + s->count + 1;
+        }
+        break;
+    case 3:
+        base = (d / s->count) * s->count;
+        period2 = ((s->count + 1) >> 1);
+        if ((d - base) < period2) {
+            next_time = base + period2;
+        } else {
+            next_time = base + s->count;
+        }
+        break;
+    case 4:
+    case 5:
+        if (d < s->count) {
+            next_time = s->count;
+        } else if (d == s->count) {
+            next_time = s->count + 1;
+        } else {
+            return -1;
+        }
+        break;
+    }
+    /* convert to timer units */
+    next_time = s->count_load_time + muldiv64(next_time, get_ticks_per_sec(),
+                                              PIT_FREQ);
+    /* fix potential rounding problems */
+    /* XXX: better solution: use a clock at PIT_FREQ Hz */
+    if (next_time <= current_time) {
+        next_time = current_time + 1;
+    }
+    return next_time;
+}
+
+void pit_get_channel_info_common(PITCommonState *s, PITChannelState *sc,
+                                 PITChannelInfo *info)
+{
+    info->gate = sc->gate;
+    info->mode = sc->mode;
+    info->initial_count = sc->count;
+    info->out = pit_get_out(sc, qemu_get_clock_ns(vm_clock));
+}
+
+void pit_get_channel_info(ISADevice *dev, int channel, PITChannelInfo *info)
+{
+    PITCommonState *pit = PIT_COMMON(dev);
+    PITChannelState *s = &pit->channels[channel];
+    PITCommonClass *c = PIT_COMMON_GET_CLASS(pit);
+
+    c->get_channel_info(pit, s, info);
+}
+
+void pit_reset_common(PITCommonState *pit)
+{
+    PITChannelState *s;
+    int i;
+
+    for (i = 0; i < 3; i++) {
+        s = &pit->channels[i];
+        s->mode = 3;
+        s->gate = (i != 2);
+        s->count_load_time = qemu_get_clock_ns(vm_clock);
+        s->count = 0x10000;
+        if (i == 0 && !s->irq_disabled) {
+            s->next_transition_time =
+                pit_get_next_transition_time(s, s->count_load_time);
+        }
+    }
+}
+
+static int pit_init_common(ISADevice *dev)
+{
+    PITCommonState *pit = PIT_COMMON(dev);
+    PITCommonClass *c = PIT_COMMON_GET_CLASS(pit);
+    int ret;
+
+    ret = c->init(pit);
+    if (ret < 0) {
+        return ret;
+    }
+
+    isa_register_ioport(dev, &pit->ioports, pit->iobase);
+
+    qdev_set_legacy_instance_id(&dev->qdev, pit->iobase, 2);
+
+    return 0;
+}
+
+static const VMStateDescription vmstate_pit_channel = {
+    .name = "pit channel",
+    .version_id = 2,
+    .minimum_version_id = 2,
+    .minimum_version_id_old = 2,
+    .fields = (VMStateField[]) {
+        VMSTATE_INT32(count, PITChannelState),
+        VMSTATE_UINT16(latched_count, PITChannelState),
+        VMSTATE_UINT8(count_latched, PITChannelState),
+        VMSTATE_UINT8(status_latched, PITChannelState),
+        VMSTATE_UINT8(status, PITChannelState),
+        VMSTATE_UINT8(read_state, PITChannelState),
+        VMSTATE_UINT8(write_state, PITChannelState),
+        VMSTATE_UINT8(write_latch, PITChannelState),
+        VMSTATE_UINT8(rw_mode, PITChannelState),
+        VMSTATE_UINT8(mode, PITChannelState),
+        VMSTATE_UINT8(bcd, PITChannelState),
+        VMSTATE_UINT8(gate, PITChannelState),
+        VMSTATE_INT64(count_load_time, PITChannelState),
+        VMSTATE_INT64(next_transition_time, PITChannelState),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static int pit_load_old(QEMUFile *f, void *opaque, int version_id)
+{
+    PITCommonState *pit = opaque;
+    PITChannelState *s;
+    int i;
+
+    if (version_id != 1) {
+        return -EINVAL;
+    }
+
+    for (i = 0; i < 3; i++) {
+        s = &pit->channels[i];
+        s->count = qemu_get_be32(f);
+        qemu_get_be16s(f, &s->latched_count);
+        qemu_get_8s(f, &s->count_latched);
+        qemu_get_8s(f, &s->status_latched);
+        qemu_get_8s(f, &s->status);
+        qemu_get_8s(f, &s->read_state);
+        qemu_get_8s(f, &s->write_state);
+        qemu_get_8s(f, &s->write_latch);
+        qemu_get_8s(f, &s->rw_mode);
+        qemu_get_8s(f, &s->mode);
+        qemu_get_8s(f, &s->bcd);
+        qemu_get_8s(f, &s->gate);
+        s->count_load_time = qemu_get_be64(f);
+        s->irq_disabled = 0;
+        if (s->irq_timer) {
+            s->next_transition_time = qemu_get_be64(f);
+            qemu_get_timer(f, s->irq_timer);
+        }
+    }
+    return 0;
+}
+
+static void pit_dispatch_pre_save(void *opaque)
+{
+    PITCommonState *s = opaque;
+    PITCommonClass *c = PIT_COMMON_GET_CLASS(s);
+
+    if (c->pre_save) {
+        c->pre_save(s);
+    }
+}
+
+static int pit_dispatch_post_load(void *opaque, int version_id)
+{
+    PITCommonState *s = opaque;
+    PITCommonClass *c = PIT_COMMON_GET_CLASS(s);
+
+    if (c->post_load) {
+        c->post_load(s);
+    }
+    return 0;
+}
+
+static const VMStateDescription vmstate_pit_common = {
+    .name = "i8254",
+    .version_id = 3,
+    .minimum_version_id = 2,
+    .minimum_version_id_old = 1,
+    .load_state_old = pit_load_old,
+    .pre_save = pit_dispatch_pre_save,
+    .post_load = pit_dispatch_post_load,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32_V(channels[0].irq_disabled, PITCommonState, 3),
+        VMSTATE_STRUCT_ARRAY(channels, PITCommonState, 3, 2,
+                             vmstate_pit_channel, PITChannelState),
+        VMSTATE_TIMER(channels[0].irq_timer, PITCommonState),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void pit_common_class_init(ObjectClass *klass, void *data)
+{
+    ISADeviceClass *ic = ISA_DEVICE_CLASS(klass);
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    ic->init = pit_init_common;
+    dc->vmsd = &vmstate_pit_common;
+    dc->no_user = 1;
+}
+
+static TypeInfo pit_common_type = {
+    .name          = TYPE_PIT_COMMON,
+    .parent        = TYPE_ISA_DEVICE,
+    .instance_size = sizeof(PITCommonState),
+    .class_size    = sizeof(PITCommonClass),
+    .class_init    = pit_common_class_init,
+    .abstract      = true,
+};
+
+static void register_devices(void)
+{
+    type_register_static(&pit_common_type);
+}
+
+type_init(register_devices);